title: Transverse mesocolon invasion in advanced gastric cancer: should we reconsider current T staging?
abstract: BACKGROUND
  According to the AJCC/UICC TNM classification, T mesocolon invasion in AGC is classified as T2b or T3 according to the presence or the absence of serosa invasion. However, many authors have considered T mesocolon invasion in AGC as T4. This study was performed to evaluate the appropriate T stage for T mesocolon invasion in AGC.
  
  
  METHODS
  From 1996 to 2008, 90 patients underwent curative gastrectomy with T mesocolon excision at the authors' institute under the suspicion of T mesocolon invasion based on surgical findings and without pathologic invasion to any other organ. Histopathologic findings were reviewed to determine whether tumors had invaded the T mesocolon. Survival data of AGC patients registered in the SNUH database (N = 9998, from 1986 to 2007) was used as reference data for comparative purposes.
  
  
  RESULTS
  A total of 27 patients (30%) had proven histopathological invasion of the T mesocolon, and a significant difference in survival rates was found between these 27 and the remaining 63 (P = .012). As compared with the SNUH database population, the survival rate of T mesocolon invasion patients differed from those of T2b (P < .001) and T3 (P = .043) patients, but was similar to that of T4 patients (P = .218). Furthermore, for N1 stage patients, the survival rate differed from those of T2b (P = .001) and T3 (P = .046) patients, but was similar to that of T4 patients (P = .744).
  
  
  CONCLUSIONS
  The T stage of T mesocolon invasion in AGC should be revised to AJCC/UICC stage T4, because the survival rate of T mesocolon invasion AGC is lower than that of stage T2b or T3.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Kong
authors.forename: Min A
authors.initials: MA
authors.lastname: Kim
authors.forename: Woo Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Lee
authors.forename: Kuhn Uk
authors.initials: KU
authors.lastname: Lee
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008646:Mesocolon / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000592:standards*; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome